Column: iPods: Hearing hazard?

When I was a freshman, way back in 2004, iPods were a relatively new commodity on campus. A handful of my friends owned the revolutionary music-listening device and attempted to convince the rest of us that this was the next big thing. Since then, iPods have dominated the portable music player market and have taken a permanent resting place in the ears of college students. MU has joined more than 50 colleges and universities nationwide by adopting the iPod as a learning tool and even recommends that all incoming journalism students meet an "audio-video player" requirement by purchasing an iPod touch.

While the technology of iPods and other portable MP3 players has given students the ability to access their media in once-unimaginable ways, students are often unaware of how much these devices are used and their long-term effects on hearing health.

Surveys have revealed the average college student listens to MP3 players for one to three hours every day, most often during exercise or while walking to class. Most students report using the factory-issued iPod earbuds and listen to music at a "medium" volume.

Although these findings may not seem alarming, the inherent design of iPods and the environment in which they are used might increase potential risk of hearing impairment. The iPod's long battery life allows users to listen to music for an almost unlimited amount of time and the factory earbuds do not block out ambient noise. This inability to cancel out unwanted noise is often compensated by users increasing the volume of the device while walking to campus, riding the bus or exercising at the gym. In addition, a significant percent of students reported using their iPods while driving a car (18 percent) or riding a bike (39 percent), activities in which reduced awareness of what's going on around them could result in serious accidents.

Although studies have found the majority of college students listened to MP3 players at safe volume levels, a small number of students reported occasional use at maximum volume levels and experienced soreness and ringing in their ears after listening sessions. A chainsaw produces 111 decibels of sound. Considering that some MP3 players can achieve maximum sound output upwards of 100 decibels, permanent hearing loss can result from just 10 minutes of continuous use at these maximum volume levels. Extended exposure to sounds 85 decibels or higher causes cilia, the delicate hair cells in your inner ear that transmit sound, to be irreversibly damaged. There also exists a misconception that music is only too loud if the people around you can hear it. Research has shown that this statement might be true for quiet environments, such as the library or a quiet room but underestimates the volume of music in almost all other conditions.

As iPods and MP3 players play an increasingly important role in classrooms and college life, students should be aware of the potential harms of using these devices. Some recommendations for maintaining hearing health include:

Follow the "80-90 rule" by limiting the volume to 80 percent of the maximum and listen no longer than 90 minutes per day, if using the factory-issued earbuds that come with the MP3 player.

Use sound-isolating earphones that block out background noise and allow for better regulation of volume in more noisy environments.

Be aware that using MP3 players in loud environments can cause listeners to increase the volume subconsciously and might increase the risk of accidents when driving or riding a bike.